For implementation of miniature, high performance metal oxide semiconductor (MOS) devices, various techniques are required. These techniques may relate to, for example, the thickness of a gate oxide film, a source/drain region, and a channel region. In particular, examples of these techniques may include a technique for reducing the thickness of a gate oxide film in order to suppress a short channel effect (SCE) generated with the increase of degree of integration of a MOS transistor, a technique for reducing a charge sharing effect by forming a source/drain region using a shallow junction, and a technique for modifying a doping profile in a channel through a retrograde ion implantation or a halo ion implantation in order to suppress a short channel effect.
In the technique for modifying the doping profile, boron (B) ions are used to perform a halo ion implantation in order to suppress the short channel effect. However, it is known that the boron ions exhibit a transient enhanced diffusion phenomenon in that they are diffused in a very sensitive response to thermal budget. Accordingly, it is not easy to attain a desired junction profile using boron doping.
Recently, as an alternative, there has been proposed a method for forming the halo region using ions having a slow diffusion speed. However, this method has a problem in that the halo region does not show its function sufficiently due to a low dopant activation level.